If skb_linearize() fails, we need to free the skb.

TSO makes skb bigger, and this bug might be the reason
Raspberry Pi 3B+ users had to disable TSO.

Fixes: 55d7de9d ("Microchip's LAN7800 family USB 2/3 to 10/100/1000 Ethernet device driver")
Signed-off-by: NEric Dumazet <edumazet@google.com>
Reported-by: NRENARD Pierre-Francois <pfrenard@gmail.com>
Cc: Stefan Wahren <stefan.wahren@i2se.com>
Cc: Woojung Huh <woojung.huh@microchip.com>
Cc: Microchip Linux Driver Support <UNGLinuxDriver@microchip.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Display the return code as decimal integer.

Fixes: 55d7de9d ("Microchip's LAN7800 family USB 2/3 to 10/100/1000 Ethernet device driver")
Signed-off-by: NCristian Birsan <cristian.birsan@microchip.com>
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>

Lan78xx driver accesses the PHY registers through MDIO bus over USB
connection. When performing a suspend/resume, the PHY registers can be
accessed before the USB connection is resumed. This will generate an
error and will prevent the device to resume correctly.
This patch adds the dependency between the MDIO bus and USB device to
allow correct handling of suspend/resume.

Fixes: ce85e13a ("lan78xx: Update to use phylib instead of mii_if_info.")
Signed-off-by: NCristian Birsan <cristian.birsan@microchip.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

lan78xx_status() will run with interrupts enabled due to the change in
ed194d13 ("usb: core: remove local_irq_save() around ->complete()
handler"). generic_handle_irq() expects to be run with IRQs disabled.

[    4.886203] 000: irq 79 handler irq_default_primary_handler+0x0/0x8 enabled interrupts
[    4.886243] 000: WARNING: CPU: 0 PID: 0 at kernel/irq/handle.c:152 __handle_irq_event_percpu+0x154/0x168
[    4.896294] 000: Modules linked in:
[    4.896301] 000: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.3.6 #39
[    4.896310] 000: Hardware name: Raspberry Pi 3 Model B+ (DT)
[    4.896315] 000: pstate: 60000005 (nZCv daif -PAN -UAO)
[    4.896321] 000: pc : __handle_irq_event_percpu+0x154/0x168
[    4.896331] 000: lr : __handle_irq_event_percpu+0x154/0x168
[    4.896339] 000: sp : ffff000010003cc0
[    4.896346] 000: x29: ffff000010003cc0 x28: 0000000000000060
[    4.896355] 000: x27: ffff000011021980 x26: ffff00001189c72b
[    4.896364] 000: x25: ffff000011702bc0 x24: ffff800036d6e400
[    4.896373] 000: x23: 000000000000004f x22: ffff000010003d64
[    4.896381] 000: x21: 0000000000000000 x20: 0000000000000002
[    4.896390] 000: x19: ffff8000371c8480 x18: 0000000000000060
[    4.896398] 000: x17: 0000000000000000 x16: 00000000000000eb
[    4.896406] 000: x15: ffff000011712d18 x14: 7265746e69206465
[    4.896414] 000: x13: ffff000010003ba0 x12: ffff000011712df0
[    4.896422] 000: x11: 0000000000000001 x10: ffff000011712e08
[    4.896430] 000: x9 : 0000000000000001 x8 : 000000000003c920
[    4.896437] 000: x7 : ffff0000118cc410 x6 : ffff0000118c7f00
[    4.896445] 000: x5 : 000000000003c920 x4 : 0000000000004510
[    4.896453] 000: x3 : ffff000011712dc8 x2 : 0000000000000000
[    4.896461] 000: x1 : 73a3f67df94c1500 x0 : 0000000000000000
[    4.896466] 000: Call trace:
[    4.896471] 000:  __handle_irq_event_percpu+0x154/0x168
[    4.896481] 000:  handle_irq_event_percpu+0x50/0xb0
[    4.896489] 000:  handle_irq_event+0x40/0x98
[    4.896497] 000:  handle_simple_irq+0xa4/0xf0
[    4.896505] 000:  generic_handle_irq+0x24/0x38
[    4.896513] 000:  intr_complete+0xb0/0xe0
[    4.896525] 000:  __usb_hcd_giveback_urb+0x58/0xd8
[    4.896533] 000:  usb_giveback_urb_bh+0xd0/0x170
[    4.896539] 000:  tasklet_action_common.isra.0+0x9c/0x128
[    4.896549] 000:  tasklet_hi_action+0x24/0x30
[    4.896556] 000:  __do_softirq+0x120/0x23c
[    4.896564] 000:  irq_exit+0xb8/0xd8
[    4.896571] 000:  __handle_domain_irq+0x64/0xb8
[    4.896579] 000:  bcm2836_arm_irqchip_handle_irq+0x60/0xc0
[    4.896586] 000:  el1_irq+0xb8/0x140
[    4.896592] 000:  arch_cpu_idle+0x10/0x18
[    4.896601] 000:  do_idle+0x200/0x280
[    4.896608] 000:  cpu_startup_entry+0x20/0x28
[    4.896615] 000:  rest_init+0xb4/0xc0
[    4.896623] 000:  arch_call_rest_init+0xc/0x14
[    4.896632] 000:  start_kernel+0x454/0x480

Fixes: ed194d13 ("usb: core: remove local_irq_save() around ->complete() handler")
Cc: Woojung Huh <woojung.huh@microchip.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Stefan Wahren <wahrenst@gmx.net>
Cc: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: NDaniel Wagner <dwagner@suse.de>
Tested-by: NStefan Wahren <wahrenst@gmx.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fixes gcc '-Wunused-but-set-variable' warning:

drivers/net/usb/lan78xx.c:3995:6: warning:
 variable event set but not used [-Wunused-but-set-variable]

It is never used, so can be removed.
Signed-off-by: NYueHaibing <yuehaibing@huawei.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As soon as the netdev is registers, the kernel can start using the
interface. If the driver connects the MAC to the PHY after the netdev
is registered, there is a race condition where the interface can be
opened without having the PHY connected.

Change the order to close this race condition.

Fixes: 92571a1a ("lan78xx: Connect phy early")
Reported-by: NDaniel Wagner <dwagner@suse.de>
Signed-off-by: NAndrew Lunn <andrew@lunn.ch>
Tested-by: NDaniel Wagner <dwagner@suse.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In lan78xx_probe(), a new urb is allocated through usb_alloc_urb() and
saved to 'dev->urb_intr'. However, in the following execution, if an error
occurs, 'dev->urb_intr' is not deallocated, leading to memory leaks. To fix
this issue, invoke usb_free_urb() to free the allocated urb before
returning from the function.
Signed-off-by: NWenwen Wang <wenwen@cs.uga.edu>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Merge the combo uses of cpu_to_le32s and memcpy.
Use put_unaligned_le32 instead.
This simplifies the code.
Signed-off-by: NChuhong Yuan <hslester96@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Merge the combo use of memcpy and lexx_to_cpus.
Use get_unaligned_lexx instead.
This simplifies the code.
Signed-off-by: NChuhong Yuan <hslester96@gmail.com>
Acked-by: NWoojung Huh <woojung.huh@microchip.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

All users of the fixed_phy_add() pass -1 as GPIO number
to the fixed phy driver, and all users of fixed_phy_register()
pass -1 as GPIO number as well, except for the device
tree MDIO bus.

Any new users should create a proper device and pass the
GPIO as a descriptor associated with the device so delete
the GPIO argument from the calls and drop the code looking
requesting a GPIO in fixed_phy_add().

In fixed phy_register(), investigate the "fixed-link"
node and pick the GPIO descriptor from "link-gpios" if
this property exists. Move the corresponding code out
of of_mdio.c as the fixed phy code anyways requires
OF to be in use.
Tested-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Current state for the lan78xx driver does not allow for changing the
MAC address of the interface, without either removing the module (if
you compiled it that way) or rebooting the machine.  If you attempt to
change the MAC address, ifconfig will show the new address, however,
the system/interface will not respond to any traffic using that
configuration.  A few short-term options to work around this are to
unload the module and reload it with the new MAC address, change the
interface to "promisc", or reboot with the correct configuration to
change the MAC.

This patch enables the ability to change the MAC address via fairly normal means...
ifdown <interface>
modify entry in /etc/network/interfaces OR a similar method
ifup <interface>
Then test via any network communication, such as ICMP requests to gateway.

My only test platform for this patch has been a raspberry pi model 3b+.
Signed-off-by: NJason Martinsen <jasonmartinsen@msn.com>

-----
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

There are a few MAC/PHYs combinations which now support > 1Gbps. These
may need to make use of link modes with bits > 31. Thus their
supported PHY features or advertised features cannot be implemented
using the current bitmap in a u32. Convert to using a linkmode bitmap,
which can support all the currently devices link modes, and is future
proof as more modes are added.
Signed-off-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The driver supports a fair amount of Wake-on-LAN modes, but is not
checking that the user specified one that is supported.

Fixes: 55d7de9d ("Microchip's LAN7800 family USB 2/3 to 10/100/1000 Ethernet device driver")
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Reviewed-by: NWoojung Huh <Woojung.Huh@Microchip.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Clang warns when a variable is assigned to itself.

drivers/net/usb/lan78xx.c:940:11: warning: explicitly assigning value of
variable of type 'u32' (aka 'unsigned int') to itself [-Wself-assign]
                        offset = offset;
                        ~~~~~~ ^ ~~~~~~
1 warning generated.

Reorder the if statement to acheive the same result and avoid a self
assignment warning.

Link: https://github.com/ClangBuiltLinux/linux/issues/129Signed-off-by: NNathan Chancellor <natechancellor@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

of_node_put has taken the null pointer check into account. So it is
safe to remove the duplicated check before of_node_put.
Signed-off-by: Nzhong jiang <zhongjiang@huawei.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Some MAC hardware cannot support a subset of link modes. e.g. often
1Gbps Full duplex is supported, but Half duplex is not. Add a helper
to remove such a link mode.
Signed-off-by: NAndrew Lunn <andrew@lunn.ch>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use skb_queue_walk() instead.

Adjust inner loop test to utilize and skb_queue_is_first().
Unfortunately we have to keep pkt_cnt around because it is
used by a latter loop in this function.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch makes some declaration more consistent.
Signed-off-by: NStefan Wahren <stefan.wahren@i2se.com>
Reviewed-by: NRaghuram Chary Jallipalli <raghuramchary.jallipalli@microchip.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Adopt the SPDX license identifier headers to ease license compliance
management.
Signed-off-by: NStefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

There is no need for this strcpy because alloc_etherdev() already
does this job.
Signed-off-by: NStefan Wahren <stefan.wahren@i2se.com>
Reviewed-by: NRaghuram Chary Jallipalli <raghuramchary.jallipalli@microchip.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We need to bail out if lan78xx_get_endpoints() fails, otherwise the
result is overwritten.

Fixes: 55d7de9d ("Microchip's LAN7800 family USB 2/3 to 10/100/1000 Ethernet")
Signed-off-by: NStefan Wahren <stefan.wahren@i2se.com>
Reviewed-by: NRaghuram Chary Jallipalli <raghuramchary.jallipalli@microchip.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We use ARRAY_SIZE to replace open code sizeof(lan78xx_regs) / sizeof(u32).
It make the code concise.
Signed-off-by: Nzhong jiang <zhongjiang@huawei.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As long the bh tasklet isn't scheduled once, no packet from the rx path
will be handled. Since the tx path also schedule the same tasklet
this situation only persits until the first packet transmission.
So fix this issue by scheduling the tasklet after link reset.

Link: https://github.com/raspberrypi/linux/issues/2617
Fixes: 55d7de9d ("Microchip's LAN7800 family USB 2/3 to 10/100/1000 Ethernet")
Suggested-by: NFloris Bos <bos@je-eigen-domein.nl>
Signed-off-by: NStefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The skb size calculation in lan78xx_tx_bh is in race with the start_xmit,
which could lead to rare kernel oopses. So protect the whole skb walk with
a spin lock. As a benefit we can unlink the skb directly.

This patch was tested on Raspberry Pi 3B+

Link: https://github.com/raspberrypi/linux/issues/2608
Fixes: 55d7de9d ("Microchip's LAN7800 family USB 2/3 to 10/100/1000 Ethernet")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NFloris Bos <bos@je-eigen-domein.nl>
Signed-off-by: NStefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Observations of VLANs dropping packets due to invalid
checksums when not offloading VLAN tag receive.
With VLAN tag stripping enabled no issue is observed.

Drop back to s/w checksums if VLAN offload is disabled.
Signed-off-by: NDave Stevenson <dave.stevenson@raspberrypi.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The chip supports stripping the VLAN tag and reporting it
in metadata.
Complete the support for this.
Signed-off-by: NDave Stevenson <dave.stevenson@raspberrypi.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

HW_VLAN_CTAG_FILTER was partially implemented, but not advertised
to Linux.

Complete the implementation of this.
Signed-off-by: NDave Stevenson <dave.stevenson@raspberrypi.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The frame abort timeout being set by lan78xx_set_rx_max_frame_length
didn't account for any VLAN headers, resulting in very low
throughput if used with tagged VLANs.

Use VLAN_ETH_HLEN instead of ETH_HLEN to correct for this.
Signed-off-by: NDave Stevenson <dave.stevenson@raspberrypi.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

random_ether_addr is a #define for eth_random_addr which is
generally preferred in kernel code by ~3:1

Convert the uses of random_ether_addr to enable removing the #define

Miscellanea:

o Convert &vfmac[0] to equivalent vfmac and avoid unnecessary line wrap
Signed-off-by: NJoe Perches <joe@perches.com>
Acked-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

A number of drivers have the following pattern:

if (np)
	of_mdiobus_register()
else
	mdiobus_register()

which the implementation of of_mdiobus_register() now takes care of.
Remove that pattern in drivers that strictly adhere to it.
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Reviewed-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Reviewed-by: NFugang Duan <fugang.duan@nxp.com>
Reviewed-by: NAntoine Tenart <antoine.tenart@bootlin.com>
Reviewed-by: NJose Abreu <joabreu@synopsys.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Modify the error messages when phy registration fails.
Signed-off-by: NRaghuram Chary J <raghuramchary.jallipalli@microchip.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Remove driver version info from the lan78xx driver.
Signed-off-by: NRaghuram Chary J <raghuramchary.jallipalli@microchip.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Adding Fixed PHY support to the lan78xx driver.
Signed-off-by: NRaghuram Chary J <raghuramchary.jallipalli@microchip.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In order to dump lan78xx family registers using ethtool, add
support at lan78xx driver level.
Signed-off-by: NRaghuram Chary J <raghuramchary.jallipalli@microchip.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add support for DT property "microchip,led-modes", a vector of zero
to four cells (u32s) in the range 0-15, each of which sets the mode
for one of the LEDs. Some possible values are:

    0=link/activity          1=link1000/activity
    2=link100/activity       3=link10/activity
    4=link100/1000/activity  5=link10/1000/activity
    6=link10/100/activity    14=off    15=on

These values are given symbolic constants in a dt-bindings header.

Also use the presence of the DT property to indicate that the
LEDs should be enabled - necessary in the event that no valid OTP
or EEPROM is available.
Signed-off-by: NPhil Elwell <phil@raspberrypi.org>
Reviewed-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

There is a standard mechanism for locating and using a MAC address from
the Device Tree. Use this facility in the lan78xx driver to support
applications without programmed EEPROM or OTP. At the same time,
regularise the handling of the different address sources.
Signed-off-by: NPhil Elwell <phil@raspberrypi.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Commit 92571a1a ("lan78xx: Connect phy early") moves the PHY
initialisation into lan78xx_probe, but lan78xx_open subsequently calls
lan78xx_reset. As well as forcing a second round of link negotiation,
this reset frequently prevents the phy interrupt from being generated
(even though the link is up), rendering the interface unusable.

Fix this issue by removing the lan78xx_reset call from lan78xx_open.

Fixes: 92571a1a ("lan78xx: Connect phy early")
Signed-off-by: NPhil Elwell <phil@raspberrypi.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

lan78xx_defer_event generates an error message whenever the work item
is already scheduled. lan78xx_open defers three events -
EVENT_STAT_UPDATE, EVENT_DEV_OPEN and EVENT_LINK_RESET. Being aware
of the likelihood (or certainty) of an error message, the DEV_OPEN
event is added to the set of pending events directly, relying on
the subsequent deferral of the EVENT_LINK_RESET call to schedule the
work.  Take the same precaution with EVENT_STAT_UPDATE to avoid a
totally unnecessary error message.
Signed-off-by: NPhil Elwell <phil@raspberrypi.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

lan78xx_read_otp tries to return -EINVAL in the event of invalid OTP
content, but the value gets overwritten before it is returned and the
read goes ahead anyway. Make the read conditional as it should be
and preserve the error code.

Fixes: 55d7de9d ("Microchip's LAN7800 family USB 2/3 to 10/100/1000 Ethernet device driver")
Signed-off-by: NPhil Elwell <phil@raspberrypi.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When using wicked with a lan78xx device attached to the system, we
end up with ethtool commands issued on the device before an ifup
got issued. That lead to the following crash:

    Unable to handle kernel NULL pointer dereference at virtual address 0000039c
    pgd = ffff800035b30000
    [0000039c] *pgd=0000000000000000
    Internal error: Oops: 96000004 [#1] SMP
    Modules linked in: [...]
    Supported: Yes
    CPU: 3 PID: 638 Comm: wickedd Tainted: G            E      4.12.14-0-default #1
    Hardware name: raspberrypi rpi/rpi, BIOS 2018.03-rc2 02/21/2018
    task: ffff800035e74180 task.stack: ffff800036718000
    PC is at phy_ethtool_ksettings_get+0x20/0x98
    LR is at lan78xx_get_link_ksettings+0x44/0x60 [lan78xx]
    pc : [<ffff0000086f7f30>] lr : [<ffff000000dcca84>] pstate: 20000005
    sp : ffff80003671bb20
    x29: ffff80003671bb20 x28: ffff800035e74180
    x27: ffff000008912000 x26: 000000000000001d
    x25: 0000000000000124 x24: ffff000008f74d00
    x23: 0000004000114809 x22: 0000000000000000
    x21: ffff80003671bbd0 x20: 0000000000000000
    x19: ffff80003671bbd0 x18: 000000000000040d
    x17: 0000000000000001 x16: 0000000000000000
    x15: 0000000000000000 x14: ffffffffffffffff
    x13: 0000000000000000 x12: 0000000000000020
    x11: 0101010101010101 x10: fefefefefefefeff
    x9 : 7f7f7f7f7f7f7f7f x8 : fefefeff31677364
    x7 : 0000000080808080 x6 : ffff80003671bc9c
    x5 : ffff80003671b9f8 x4 : ffff80002c296190
    x3 : 0000000000000000 x2 : 0000000000000000
    x1 : ffff80003671bbd0 x0 : ffff80003671bc00
    Process wickedd (pid: 638, stack limit = 0xffff800036718000)
    Call trace:
    Exception stack(0xffff80003671b9e0 to 0xffff80003671bb20)
    b9e0: ffff80003671bc00 ffff80003671bbd0 0000000000000000 0000000000000000
    ba00: ffff80002c296190 ffff80003671b9f8 ffff80003671bc9c 0000000080808080
    ba20: fefefeff31677364 7f7f7f7f7f7f7f7f fefefefefefefeff 0101010101010101
    ba40: 0000000000000020 0000000000000000 ffffffffffffffff 0000000000000000
    ba60: 0000000000000000 0000000000000001 000000000000040d ffff80003671bbd0
    ba80: 0000000000000000 ffff80003671bbd0 0000000000000000 0000004000114809
    baa0: ffff000008f74d00 0000000000000124 000000000000001d ffff000008912000
    bac0: ffff800035e74180 ffff80003671bb20 ffff000000dcca84 ffff80003671bb20
    bae0: ffff0000086f7f30 0000000020000005 ffff80002c296000 ffff800035223900
    bb00: 0000ffffffffffff 0000000000000000 ffff80003671bb20 ffff0000086f7f30
    [<ffff0000086f7f30>] phy_ethtool_ksettings_get+0x20/0x98
    [<ffff000000dcca84>] lan78xx_get_link_ksettings+0x44/0x60 [lan78xx]
    [<ffff0000087cbc40>] ethtool_get_settings+0x68/0x210
    [<ffff0000087cc0d4>] dev_ethtool+0x214/0x2180
    [<ffff0000087e5008>] dev_ioctl+0x400/0x630
    [<ffff00000879dd00>] sock_do_ioctl+0x70/0x88
    [<ffff00000879f5f8>] sock_ioctl+0x208/0x368
    [<ffff0000082cde10>] do_vfs_ioctl+0xb0/0x848
    [<ffff0000082ce634>] SyS_ioctl+0x8c/0xa8
    Exception stack(0xffff80003671bec0 to 0xffff80003671c000)
    bec0: 0000000000000009 0000000000008946 0000fffff4e841d0 0000aa0032687465
    bee0: 0000aaaafa2319d4 0000fffff4e841d4 0000000032687465 0000000032687465
    bf00: 000000000000001d 7f7fff7f7f7f7f7f 72606b622e71ff4c 7f7f7f7f7f7f7f7f
    bf20: 0101010101010101 0000000000000020 ffffffffffffffff 0000ffff7f510c68
    bf40: 0000ffff7f6a9d18 0000ffff7f44ce30 000000000000040d 0000ffff7f6f98f0
    bf60: 0000fffff4e842c0 0000000000000001 0000aaaafa2c2e00 0000ffff7f6ab000
    bf80: 0000fffff4e842c0 0000ffff7f62a000 0000aaaafa2b9f20 0000aaaafa2c2e00
    bfa0: 0000fffff4e84818 0000fffff4e841a0 0000ffff7f5ad0cc 0000fffff4e841a0
    bfc0: 0000ffff7f44ce3c 0000000080000000 0000000000000009 000000000000001d
    bfe0: 0000000000000000 0000000000000000 0000000000000000 0000000000000000

The culprit is quite simple: The driver tries to access the phy left and right,
but only actually has a working reference to it when the device is up.

The fix thus is quite simple too: Get a reference to the phy on probe already
and keep it even when the device is going down.

With this patch applied, I can successfully run wicked on my system and bring
the interface up and down as many times as I want, without getting NULL pointer
dereferences in between.
Signed-off-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>